Internet telephone communication for communicating with external apparatus via the Internet is known. Personal computers were generally utilized as terminal units for performing the Internet telephone communication in the initial stages of dissemination of the Internet telephone communication. However, in recent years, an increasing number of telephone sets are utilized as terminal units for performing the Internet telephone communication.
For instance, Japanese unexamined patent application publication No. 2006-270252 describes a mobile telephone that can be utilized for performing the Internet telephone communication. The mobile telephone stores in advance an operation program for performing the Internet telephone communication, (to be referred to as “Internet telephone program” hereinafter). After the mobile telephone is connected to a personal computer via a USB cable, the personal computer automatically starts executing the Internet telephone program so that the mobile telephone can perform the Internet telephone communication.